1. Field of the Invention:
This invention relates generally to improvements in the construction of bats.
More particularly, this invention relates to a safety means for baseball bats which does not affect the weight or balance of the bat.
2. Description of the Related Art:
Wooden baseball bats occasionally fail in use breaking at the handle upon impact with a pitched ball. The barrel portion of the bat separates from the handle and flies through the air. There is the likelihood of serious injury if the heavy barrel portion strikes a person.
It has been proposed in the prior art to provide various means to reinforce the bat and to prevent its breaking or to keep the parts from separating in the event the bat did break. One such prior art approach is illustrated by U.S. Pat. No. 1,603,904 to Cohn. Cohn discloses a baseball bat having a reinforcing rod extending axially the length of the bat. The reinforcing rod is described as a shaft, preferably of steel, secured at one end by threaded engagement with a base plate. The other end of the shaft is screwed into an elongated boss on a cap which is secured to the end of the bat.
A later patent to the same inventor, U.S. Pat. No. 1,665,195, describes generally a bat having a central longitudinal passage therethrough and having an enlarged passage bore at the upper and lower extremities of the bat. A metallic rod, screw threaded at both ends, is disposed in the passage. Threaded metal plugs are disposed in the enlarged passage bore at the bat ends and are screw threaded onto the rod. The rod acts as a reinforcing member which, the inventor asserts, will prevent bat breakage in most instances. Should the bat break, the metal plugs on the shaft ends will hold the broken bat pieces together.
More recently, there has been a trend toward using metal bats, especially in the game of softball. Such bats are usually made of a die cast aluminum or magnesium alloy. Metal bats do provide certain advantages over wooden bats in that metal bats seldom crack split, or break. Even though metal bats provide safety advantages over wooden ones, use of metal bats has not been well received by serious baseball players and in fact metal bats are not allowed for use in many leagues.
Even though metal bats are inherently less susceptible to breakage in use than are wooden ones, the prior art nevertheless discloses the use of reinforcing members extending axially the length of a metal bat. One such disclosure is found in U.S. Pat. No. 3,801,098 to Gildenmeister. That patent discloses a hollow, die cast metal bat having the barrel end open and having a knob at the end of the handle portion. The interior volume of the bat is filled with a structural foam, such as a rigid polyurethane foam, and a cap is then formed over the barrel end of the bat. A wire extending axially within the rigid foam extends the length of the bat and is anchored at its ends adjacent the bat knob and cap.
Another approach to the manufacture of reinforced metal bats is shown in a patent to Krieger, U.S. Pat. No. 4,056,267. Krieger produces a bat having a unitary metal skin structure and having a safety-strengthening device in the interior of the bat. The bat structure is die cast from a metal such as magnesium and an end cap of the same metal is welded onto the end of the bat. Before the end cap is welded in place, a strengthening device comprising a metal rod having an anchoring means at each end is placed into the hollow bat. Thereafter, the interior of the bat is filled with a resilient foam material which strengthens the structure and dampens vibrations. The strengthening device serves a dual purpose. It acts like a backbone or spine for the bat giving the bat extra longitudinal strength which reduces the tendency of the bat to crack. it also serves to prevent the complete separation of the broken piece of the bat when there occurs a sudden fracture of the entire bat.
Reinforced bats of the kind disclosed by the two Cohn patents have a number of serious disadvantages which have precluded their acceptance for use in games. The steel reinforcing rod used by Cohn is far stiffer than is the wood which it replaces and is far higher in specific gravity. Consequently, the flexibility and feel of the bat is considerably changed. The end caps and base plates which Cohn uses to secure his steel reinforcing rod are also of metal which adds weight to the bat and significantly changes its balance. Metal bats of the kind described in the Gildemeister and Krieger patents are commonly used in amateur play, particularly in the game of softball,but have not found acceptance with serious players or in professional baseball.
Even though wooden bats frequently break in use, thus creating the possibility of injury, the safety measures and alternative materials for bat construction proposed by the prior art have in large part been rejected. No approach taken in the prior art prevents the separation of the broken piece of a bat from the handle portion without also adversely affecting the weight, balance, feel, flexibility and sound of the traditional wooden bat. Hence, ball players can readily appreciate the advantages offered by a bat construction which preserves the characteristics of the traditional bat while preventing a broken piece from completely separating from the handle portion.